THE INCREAsE of greenhouse gas concentrations in the Earth's atmosphere, above natural levels, is causing anthropogenic changes to Earth's climate. The temperature at the Earth's surface has shown a significant and rapid rise since the 1990s, compared to the past two millennia. It is challenge for scientists to attribute these known changes to specific mechanisms. Some of the complex feedback processes that add to these changes are not fully understood.
The energy balance, the distribution of energy in space (or Earth's atmosphere), and temporal energy variations characterize the Earth's climate system. The Earth's radiative energy balance is governed by the balance between solar radiation and absorption by the Earth and subsequent radiation from the Earth to outer space. The Earth absorbs solar shortwave radiation in the daytime, and emits thermal infrared or longwave radiation back to outer space to maintain the heat energy balance. However, this energy balance is more imbalanced recently, because of the many components of the Earth-atmosphere system, such as clouds or aerosols and other radiation scattering particles present in the atmosphere.
The National Aeronautics and Space Administration (NASA) CERES (Clouds and the Earth's Radiant Energy System) instrument on the Tropical Rainfall Measuring Mission (TRMM) and Terra satellite mission provide a new set of Earth radiation balance data. Along with these data and a 16-year record of the Earth Radiation Budget Satellite (ERBS), NASA has compiled the 22 years of accurate satellite observed broadband radiative fluxes, showing the huge energy imbalance or long-wave anomalies since 1995.
Was this article helpful?